Refrigeration system



y 1934- w. E. ZIEBER I 1,960,471

' REFRIGERATION SYSTEM Filed Sept. 15, 1932 .2 Shets-Sheet 1 3maent or Gttornegs May 29, 1934.

w. E. ZIE B ER REFRIGERATION SYSTEM Filed Sept. 15 1932 2 Sheets-Sheet C(ttomegs Patented May 29, 1934 REFRIGERATION SYSTEM William E. Zieber, York, Pa, assignor to York Ice Machinery Corporation,

tion of Delaware York, Pa., a corpora- Application September 15, 1932, Serial No. 633,343

14 Claims.

The present invention relates to refrigeration systems, and particularly to the supply of refrigerant from a single condenser to a plurality of evaporators.

In systems of the multiple evaporator type, especially wherein evaporators at different levels are fed from one condenser, it is diflicult to maintain a pressure in the system suflicient to supply all of the evaporators so as to obtain full refrigerating effect in each evaporator. This difficulty is overcome in the present arrangement by first having the refrigerant pass through a high pressure float valve, and interposing in the feed line, preferably between the said float valve and the last of the series of evaporators, a pressure relief valve designed to maintain an intermediate pressure in the system. The intermediate evaporator-s are connected to the feed line between the high pressure float and the relief valve, thus insuring a definite supply of pressure for these evaporators, and an expansion valve, preferably a low pressure float valve, controls how of refrigerant to each intermediate evaporator.

This arrangement has the further advantage that all of the floats operate more satisfactorily and have longer life because, pressure difierences are reduced.

The invention is more fully described hereinafter, and will be understood when taken with the accompanying drawings, in which:

Fig. 1 is a diagrammatic illustration of one embodiment of the invention, a single compressor and one suction line being employed; and

Fig. 2 is a diagrammatic showing of a similar system in which there are two compressors, each having its own suction line to separate evaporators.

In Fig. 1, the compressor is indicated at ll, and the condenser at 12. Condensed refrigerant is drained from the condenser into feed line 13, the flow thereof being controlled by high pressure float valve 14. By-pass 15 and cut-off valves 16, 17 and 18 permit passage ofrefrigerant around the float valve when necessary.

As shown in the drawings, three evaporators be maintained at or about 155 pounds gage, while the relief valve will be set to open somewhere between pounds and 120 pounds gage, depending on the load to be carried by, and the locations of, evaporators 19 and 20. By maintaining the intermediate pressure sufilciently --high, frost and sweat on the pipes connecting the condenser with the relief valve and on the branch lines feeding the intermediate evaporators is obviated, thus eliminating the need for insulation on these lines.

The evaporators are provided .with suction traps 26, 2'7, 28, to which suction branch pipes 29, 31 and 32 are connected, the latter in turn being connected with suction line 33 returning evaporated refrigerant to compressor 11. The supply of refrigerant to evaporators 19 and. 20 is controlled by low pressure float valves 34, 35, while evaporator 21 depends on excess refrigerant passing through relief valve 25 for its supply of refrigerant.

Suitable by-pass connections 36 and cut-0d valves 37 are associated with each of the float valves 34, 35,-whereby refrigerant may be fed direct to the evaporators, or the latter cut out for repairs. Oil pots 38 at the lower end of each evaporator are provided to receive oil carried over into the evaporator.

The suction pressures of the several evaporators may be manually controlled, but there is shown in Fig. 1, automatic suction controls responsive to temperature conditions in the chambers being refrigerated. These automatic means comprise solenoid operated valves 39 in each of the branch suction lines, and switches 41 actuated by thermostats 42. The switches are operable to close or open the solenoid circuits upon predetermined variations in temperature in the refrigerated chambers.

Solenoid operated inlet valves 43 are also provided for evaporators 19 and 20, the solenoids being in parallel with those on valves 39 for the respective evaporators. Around each of the suction valves is a by-pass 44 provided with suitable cutofl valves and having therein a relief valve 45 set at approximately 200 pounds gage to prevent excessive pressures in the evaporators when, for any reason, the usual suction connection is closed. Switches 41 may be connected with the compressor motor in order that the motor may be automatically cut out when all of the evaporators have been shut down, or, if desired, the motor may be controlled by a suction pressure switch.

From the foregoing description it will be tip-- parent that the several evaporators are supplied with refrigerant from a single condenser through a high pressure float valve, and that sufficient pressure is maintained in the intermediate feed line by means of a relief valve to insure uniform supply of refrigerant to each of the intermediate evaporators, regardless of their relative positions. The suction connection to each evaporator is controlled independently of the other evaporator, so that the temperature of the refrigerated chambers may differ over a wide range of requirements. It is also obvious that pressure differentials across the float valves are reduced, thus minimizing erosion and leakage.

In Fig. 2, there are shown two compressors, 11, 11, discharging into the common condenser 12. High pressure float valve 14 and feed line 13 have the same relation to the condenser and evaporators as in Fig. 1. Evaporator 20 is connected to feed line 13 by branch pipe 23 between float valve 14 and relief valve 25. It is to be understood that other intermediate evaporators may be connected to the feed line between. float valve 14 and relief valve 25 and that the several evaporators are controlled by room thermostats.

As in Fig. 1, the supply of refrigerant to evaporator 20 is controlled by low pressure float valve 35 and to evaporators 21 by relief valve 25."

Suction traps. 2'7, 28 are provided for the evaporators. Instead of a common suction return line, there are, in this form of the invention, separate return lines 33, 33 from the evaporators 21, 20 to compressors 11, 11',

Except for the employment of a plurality of compressors operating on different suction pressures, and separate return lines of the evaporators, the operation of the modified form of' the invention illustrated in Fig. 2 is similar to that described with respect to Fig. 1.

The arrangement of elements in the systems shown and described is merely illustrative of the principle of the invention, and it not intended to limit its application to those systems.

Modifications and rearrangement of the parts are contemplated in the invention as defined in the claims.

What is claimed is,--

1. In a refrigeration system including a condenser, a liquid feed line, and a plurality ofevaporators; means in said feed line controlling flow of refrigerant from said condenser. to said evaporators; a relief valve responsive to a predetermined pressure and interposed in the feed ,linebetween said flow controlling means and one of the evaporators; and means connecting another of said evaporators with said feed line, saidlast-mentioned means being connected to the feed line intermediate the flow controlling means and the relief valve.

2. In a refrigeration system including a condenser, a liquid feed line and a plurality of evaporators; a relief valve interposed in the feed line between the condenser and one of the evaporators and responsive to a predetermined pressure in the feed line; a branch connection respectively. There is no necessity, therefore, to provide sucto another of said evaporators, said branch being connected to the feed line intermediate the condenser and. said relief valve; and a valve in the branch connection.

3. In a refrigeration system including a condenser, a liquid feed line, and a plurality of evaporators; a float valve controlling flow of refrigerant from the condenser to the feed line; valve means for maintaining a predetermined pressure in said feed line; means for connecting one of said evaporators with said valve means; and means for connecting another of said evaporators with said feed line intermediate said float valve and-said valve means.

4. In a refrigeration system including a condenser, a liquid feed line, and a plurality of evaporators; a float valve controlling flow of re-' frigerant from the condenser to the feed line; a relief valve for maintaining a predetermined pressure in said feed line; means for connecting one of said evaporators with said relief valve; a branch conduit connecting another of said evaporators with said feed line intermediate said float valve and said relief valve; and a valve in said branch conduit.

5; In a refrigeration system, a compressor; a condenser; a liquid feed line; a plurality of evaporators; an automatic relief valve interposed in the feed line between the condenser and one of the evaporators; a branch connection to another of said evaporators, said branch being connected to the feed line intermediate the condenser and said relief valve; and means for controlling the supply of refrigerant to said evaporators. l

6. In a refrigeration system including a compressor, a condenser, a liquid feed line, and a plurality of evaporators; a relief valve interposed in the feed line between the condenser and one of the evaporators and responsive to a predetermined pressure in the feed line; a

branch connection to another of said evaporators, said branch being connected to the feed line intermediate the condenser and said relief valve; and thermally responsive means controlling the supply of refrigerant to said evaporators.

'7. In a refrigeration system including a compressor, a condenser, a liquid feed line, and a plurality of evaporators; -a relief valve interposed in the feed line between the condenser and one of the evaporators and responsive to a predetermined pressure in the feed line; a branch connection to another of said evaporators, said branch being connected to the feed line intermediate the condenser and said relief valve; a suction conduit connecting said evaporators and said compressor; and thermally responsive means controlling the suction pressures of said evaporators interposed between each evaporator and the suction conduit.

8. In a refrigeration system including a plurality of compressors, a condenser connected to said compressors; a liquid-feed line; a plurality 9. In a refrigeration system including a plurality of compressors, a condenser connected to said compressors; a liquid feed line; a plurality of evaporators; a relief valve interposed in the feed line between the condenser and one of the evaporators and responsive to a'predetermined pressure in the feed line; a branch connection to another of said evaporators, said branch being connected to the feed line intermediate the condenser and said relief valve; a suction conduit connecting said first mentioned evaporator with one of said compressors; a second suction conduit connecting said other evaporator with another of said compressors; and thermally responsive means for regulating the supply of refrigerant to said evaporators.

10. The combination of a refrigerating circuit of the compressor-condenser-evaporator circuit type, including a plurality of evaporators connected in parallel; an automatic valve controlling flow of liquid refrigerant from the condenser to all of said'evaporators; and a relief valve interposed between said automatic valve and at least one of said evaporators.

11. The combination of a refrigerating circuit of the compressor-condenser-evaporator circuit type, including a plurality of evaporators connected in parallel; a high-side float valve controlling discharge of refrigerant from said condenser to all of said evaporators; and a pressure relief valve interposed between said float valve and at least one of said evaporators.

12. In a refrigerating system, the combination of a compressor; a condenser; a liquid line; a high side float valve interposed between the condenser and the liquid line; a suction line leading to the compressor; a plurality of evaporators connected in parallel between the liquid line and the suction line; a pressure reducing valve interposed between the liquid line and one of said evaporators; and flow controlling valves interposed between the liquid line and the remaining evaporators.

13. In a refrigerating system, the combination of a compressor; a condenser; a liquid line; a high side float valve interposed between the condenser and the liquid line; a suction line leading to the compressor; a plurality of evaporators connected in parallel between the liquid line and the suction line; a pressure reducing valve interposed between the liquid line and one of said evaporators; and low side float valves interposed between the liquid line and the remaining evaporators.

14. A refrigerating systemcomprising a compressor; a condenser; a liquid line; 'a high side float valve interposed between the condenser and the liquid line; a suction line leading to the compressor; at least one evaporator connected between the liquid line and the suction line; a low side float valve interposed between the liquid line and said evaporator; and means for maintaining a feeding liquid pressure on said low side float valve comprising a pressure reducing valve connected to the liquid line at a point relatively remote from the compressor, and an evaporator fed by said pressure reducing valve and connected to said suction line.-

- WILLIAM E. ZIEBER. 

